_herbivorous_, and some will eat anything almost that comes before them--these would be called, and very appropriately so, _omnivorous_. Let us speak of carnivorous larvæ first. The larvæ which have carnivorous propensities render themselves often truly terrible to the insect world around them. The most mighty warrior that ever lived in his whole career never slew half so many of his own species as the larva of a beautiful fly does of _aphides_ in a few hours. Well does Réaumur call them the "lions of the aphides," and thus does he describe their method of proceeding:-- [Illustration: _Lion of the Aphides._] "There is no beast of prey in nature who hunts so entirely at his ease as does this larva. Resting upon a twig or a leaf, he is surrounded on every side by the insects on which he feeds; often, indeed, they touch his sides, and he is able to catch hundreds of them without changing his position. Not only do the poor little aphides not fly from him, but they may be often seen creeping over the body of their enemy. It is only after the larva has eaten up the greater number of his prey around him, that he has any need to remove to a spot as thickly inhabited by them as that in which he has been making his cruel ravages. In order to observe the manner in which he attacks them, the best plan is to take him, put him between two leaves, and shut him up in a box for ten or twelve hours to sharpen his appetite. After this fast he must be placed on some spot where the aphides are found in abundance. Immediately he begins exploring around for prey, which he does simply by the sense of touch, as he does not appear to be able to see. At length an unhappy insect comes within his reach. Brandishing a trident with which he is armed, he immediately transfixes the insect, just as we take up a morsel of food upon a fork!" The little creature is then sucked into a sort of cavity like the neck of a bottle, where it is retained by a couple of pins until its juices are emptied by the destroyer, when he casts it away, now nothing more of it being left but a dry, shrivelled, empty skin. The aphis-lion, however, loses no time, and presently seizes another, which he pierces and sucks dry as quickly as the last.[D] When very hungry he will devour one a minute. Réaumur says, "I have seen him eat twenty of these insects one after another in twenty minutes; nor did this satisfy him: for in the course of two hours he devoured more than a hundred insects with which I supplied him!" These larvæ do repose a little, but never for long, for they are seldom without some prey in hand. "I have seen," adds the last author, "twigs of the elder seven or eight inches in length entirely covered with these insects, (the _aphides_,) and in four days' time there remained not one alive."